PURPOSE: To realize a semiconductor device with the inter-groove distance greatly reduced by a method wherein impurity similar to the substrate in conductivity type is introduced into a portion at the least of a groove region.
CONSTITUTION: Impurity similar to a P-type silicon substrate 1 in conductivity type is introduced into a portion at the least of a groove region. For example, a field oxide film 4 is formed on the surface of the P-type silicon substrate 1, whereafter a groove-forming mask is built of a silicon oxide film 11, silicon nitride film 12, and silicon oxide film 13. A process follows wherein a groove is formed by reactive ion etching, the silicon oxide film 13 is removed, and then a silicon oxide film 14 and polycrystalline silicon film 15 are formed. Boron is introduced into the polycrystalline silicon film 15 and then heat treatment is accomplished for the diffusion of the boron uniformly into the silicon substrate 1 along the side walls of the groove. The films 19, 15, 14, 12, and 11 are removed, and a silicon oxide film 2 is formed. A plate 3 of polycrystalline silicon is deposited to be worked into a prescribed shape for the formation of a capacitor.
OZAWA MASAMI
YAGI KUNIHIRO
SUNAMI HIDEO
KURE TOKUO
